Optical fiber glass eccentricity measurement device and measurement method

Abstract

Provided is a glass eccentricity measurement device which includes an irradiation unit that irradiates a side surface of a coated glass fiber obtained by coating the striated glass with light, and a light receiving unit that receives light scattered and/or refracted following irradiation of the side surface of the coated glass fiber therewith, and measures an eccentricity of the glass in the coated glass fiber by a pattern of brightness and darkness in the light received by the light receiving unit, in which three or more sets including the irradiation unit and a screen are provided around the coated glass fiber, and the sets are arranged respectively in directions having different angles on a circumference centered on the coated glass fiber.

The invention claimed is: 
     
       1. An optical fiber glass eccentricity measurement device comprising:
 an irradiation unit that irradiates with light a side surface of an optical fiber with a coating layer on a striated glass; and 
 a light receiving unit that receives light scattered and/or refracted following irradiation of the side surface of the optical fiber therewith, 
 the glass eccentricity measurement device for measuring the eccentricity of the glass in the optical fiber based on patterns of brightness and darkness in the light received by the light receiving unit, wherein 
 three or more sets each including the irradiation unit and the light receiving unit are provided around the optical fiber, 
 the sets are respectively arranged in directions having different angles on a circumference centered on the optical fiber, and 
 a first irradiation unit and a second irradiation unit, each of which is one of the irradiation units in the three or more sets, are arranged at positions facing each other with the optical fiber interposed therebetween. 
 
     
     
       2. The optical fiber glass eccentricity measurement device according to  claim 1 , wherein
 the sets are arranged in directions that are equiangular on the circumference centered on the optical fiber. 
 
     
     
       3. The optical fiber glass eccentricity measurement device according to  claim 1 , wherein
 the first irradiation unit and the second irradiation unit are each a light emitting unit. 
 
     
     
       4. The optical fiber glass eccentricity measurement device according to  claim 1 , wherein
 the first irradiation unit is a light emitting unit, and 
 the second irradiation unit is a reflection mirror that reflects the light emitted from the light emitting unit, wherein the light reflected by the reflection mirror is used as irradiation light and a side surface of the optical fiber is irradiated with the irradiation light. 
 
     
     
       5. The optical fiber glass eccentricity measurement device according to  claim 3 , further comprising:
 an arc-shaped reflection unit along the circumference centered on the optical fiber at a position facing the second irradiation unit on the circumference centered on the optical fiber, wherein 
 a first light receiving unit and a second light receiving unit, each of which is one of the light receiving units, are arranged side by side along the axial direction of the optical fiber at the same angular position on the circumference centered on the optical fiber, 
 the first light receiving unit is a light receiving unit that receives the light scattered and/or refracted following direct irradiation of the side surface of the optical fiber therewith from the first irradiation unit, and 
 the second light receiving unit is a light receiving unit that receives the light scattered and/or refracted following irradiation of the side surface of the optical fiber with the irradiation light by the second irradiation unit, and then further reflected by the reflection unit. 
 
     
     
       6. An optical fiber glass eccentricity measurement method, comprising:
 an irradiation step of irradiating a side surface of an optical fiber including a coating layer coated on a striated glass with light from four directions having different angles on a circumference centered on the optical fiber; 
 a light receiving step of receiving the light scattered and/or refracted following irradiation of the side surface of the optical fiber therewith from the three or more directions; and 
 a measuring step of measuring an eccentricity of the glass in the optical fiber based on a pattern of brightness and darkness in the received light, 
 wherein the irradiation step includes irradiating the side surface of the optical fiber with light respectively from two first irradiation units and two second irradiation units, 
 the two first irradiation units are arranged in directions having different angles on the circumference centered on the optical fiber, and 
 the two second irradiation units are arranged at positions facing each other with the optical fiber interposed therebetween. 
 
     
     
       7. The optical fiber glass eccentricity measurement method according to  claim 6 , wherein
 in the irradiation step, the light is emitted from three or more directions that are equiangular on the circumference centered on the optical fiber. 
 
     
     
       8. The optical fiber glass eccentricity measurement method according to  claim 6 , wherein
 the two first irradiation units and the two second irradiation units are each a light emitting unit, and 
 in the light receiving step, 
 the light scattered and/or refracted following irradiation of the side surface of the optical fiber therewith from the four directions are received. 
 
     
     
       9. The optical fiber glass eccentricity measurement method according to  claim 6 , wherein
 the two first irradiation units are each a light emitting unit, 
 the two second irradiation units are each a reflection mirror that reflects the light emitted from a respective one of the light emitting units, and 
 in the light receiving step, 
 the light scattered and/or refracted following irradiation of the side surface of the optical fiber therewith from the four directions are received. 
 
     
     
       10. The optical fiber glass eccentricity measurement method according to  claim 8 , wherein
 in the light receiving step, 
 light is received respectively by 
 two first light receiving units that respectively receive the light scattered and/or refracted following direct irradiation of the side surface of the optical fiber therewith from the two first irradiation units, and 
 two second light receiving units that respectively receive the light scattered and/or refracted following direct irradiation of the side surface of the optical fiber therewith from the two second irradiation units, and further reflected by two arc-shaped reflection units which are respectively arranged at positions facing the second irradiation units on the circumference centered on the optical fiber and are along the circumference centered on the optical fiber, and 
 the first light receiving unit and the second light receiving unit are arranged side by side along the axial direction of the optical fiber at the same angular position on the circumference centered on the optical fiber.